


Yes Sensei!

by Dragonpie



Category: DRAMAtical Murder - All Media Types
Genre: Ambiguous Age, Anal Fingering, Anal Sex, Begging, Hand Jobs, Happy Early Christmas, Im definetely going to hell, M/M, Masturbation, Mildly Dubious Consent, Pain, Porn With Plot, Praise Kink, Rough Sex, Sexual Tension, Slutty!Sei, Teacher-Student Relationship, at first, idk he seems to like it????, kind of, oh boy here we go - Freeform
Language: English
Status: Completed
Published: 2016-12-09
Updated: 2016-12-09
Packaged: 2018-09-07 11:15:04
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,664
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8798743
Author URL: https://archiveofourown.org/users/Dragonpie/pseuds/Dragonpie
Summary: Sei's been failing Maths for weeks now and isn't sure why. His answers are all correct, but Mizuki-Sensei keeps failing him anyway! Sei's determined to get to the bottom of things no matter the cost.Alternatively: that time i nearly killed myself to write three slutty!Sei scenes into one gargantuan 5000 smut fic.





	

**Author's Note:**

> Summary has almost nothing to do with the plot. Yeah basically Mizuki is a blackmailing teacher and they totally bang. lmao i'm totally going to hell for this. also Clear is there because i broship him and Sei so hard. They've totally got broners for each other.

Sei remembered a time where he had dreams and aspirations. A time before high school math, when he had a real chance at becoming something. He’d been an idealistic kid who believed in the natural good of people.

That seemed like such a long time ago – when in reality it was likely that only a few months had gone by. He looked back fondly on those days as if his youth had slipped away decades ago, leaving him the hopeless shell of a student he now found himself to be.

Where had it all started going downhill? He’d never failed anything! Now he had an entire stack of failed math tests piled up in a drawer at home. He kept hoping to do better the next time, but he was always presented with the same result.

A capital _‘F’_ stood in the corner of the paper, stark red against the otherwise pristine white. A thin red circle encased it, looping around twice in a manner that seemed rather rushed. Almost as though the outcome were decided before the paper was even read.

The familiar sight had Sei’s heart sinking into his stomach, more so than the smirk his teacher wore, allowing a brief glance at his expression before moving on to the next student.

He felt like crying. He’d spent a few extra hours studying – Clear had _insisted_ on helping. But it didn’t matter; Mizuki-Sensei had it out for him. He’d been purposefully failing Sei since halfway through the semester. He seemed to take some sort of perverse pleasure from it too! Like bringing Sei to the verge of tears was the only thing that kept him going.

“Granny’s gonna kill me when she finds out,” Sei mumbled, slumping against his desk.

Clear gave him a sympathetic look from across the room, and held up his own test. He’d scored 100 – of course he had. They probably had the same answers too.

Clear mouthed the words, _“you okay?”_ it was a miracle he’d forgotten not to shout.

Sei lifted his head enough to nod.

_“I’ll be fine.”_

Sei thought it was pointless to go through the test. He knew before even looking, that every question was decorated with a loopy red _x._ he followed along dejectedly, as the class went over their answers. He didn’t bother to raise his hand or participate at all; it would only lead to being called out for failing.

He’d learned his lesson quickly. Clear liked to say he’d been shamed into submission. Sei didn’t have energy left to argue.

They skimmed through four pages. Sei noted bitterly, every answer that made it onto the board was already recorded down in front of him. When he flipped onto the fifth and final page, Sei noticed a small red note written in the bottom corner, suggesting that he remain behind after class. What was that supposed to mean? He looked up, startled to see his teacher looking back, a genuine smile on his face.

Something didn’t feel right, but Sei needed to know what was going on.

The bell rang only ten minutes later. It was the final class of the day and most students were eager to leave. There was no homework given out. The class was dismissed almost immediately.

Clear wasted no time rushing to Sei’s side.

“Wow another zero! Are you sure you’ll be okay?”

“Yeah it’s okay. Just don’t tell Aoba.”

“I’ll try not to,” Clear said. He reached over and gripped Sei’s shoulders, looking him directly in the eye. “Your luck is going to change,” he nodded firmly and pulled away, beginning to rush out of the class, _already_ running behind his curfew. “Hang in there, okay!” he called out. His voice vanished into the crowded hall.

Sei couldn’t help smiling despite himself. He always found Clear’s energy infectious – endearing even. However it was short lived; the class wasn’t very big and soon he was the last student left. Mizuki was busy clearing the blackboard, and made no effort to acknowledge Sei’s presence.

For a few seconds he did nothing – simply let himself stew in the awkwardness of the situation. Eventually he decided to stand up and make his way to the front of the room.

Sei cleared his throat. He earned an indifferent look for his efforts. Mizuki waved his hand towards Sei, encouraging him to speak as though staying behind had been his idea.

Really, maybe it had been.

“Uh Sensei, I’ve been meaning to talk to you about this for a while,” Sei did his best to stay calm, and not let his nerves get to him. “I-I’d like to know why you’ve been failing me.”

“Why? Well why would I fail _any_ student? You didn’t score enough points for a passing grade.”

“But – But–” Sei slammed his test papers down onto his teachers desk, with more force than he’d intended. “All my answers are right!”

“I can’t review a test once I’ve given it back. For all I know you could’ve changed the answers.”

“What?  But – I–”

Mizuki placed the duster down, and turned to face Sei. The way his eyes were lit up, Sei could’ve mistaken him for a kid set loose in a toy store.

“Do you always have trouble with words, or is this just for me?”

Sei could feel his face heating up. He wanted to leave.

“Look I understand it’s difficult; nobody likes to fail,” Mizuki said. He came around to stand in front of Sei. “But I’m _sure_ we can work something out.”

Sei took a step back, and another. Mizuki followed him step for step, and Sei glanced cautiously towards the door.

“What are you – what do you mean?”

Mizuki reached out to tuck a stray strand of hair behind Sei’s ear, sending a shiver down his spine. He lost all sense of thought when that same hand entangled in his hair and forced him into a kiss. Mizuki’s other hand gripped his waist tightly, pulling him forward so Sei’s small body was trapped against his own.

Sei’s mind went blank for a moment. His eyes drifted closed and his back arched against his will when he felt Mizuki’s teeth nipping and tugging at his bottom lip. In the back of his mind he wondered if it was supposed to hurt, while the rest of him was preoccupied by how good it actually felt. He opened his mouth hesitantly, immediately assaulted by the taste of coffee, and the feel of Mizuki’s tongue against his own. He let a small moan escape his mouth, a gasp following shortly after when he flicked his tongue out experimentally, only to have it bitten.

He was inexperienced, and so Sei let his teacher take the lead. He melted into the sensations as they soaked into his hormone-fuelled mind. The kiss became a mess of saliva and teeth, and Sei struggled to get _more._ With his head held in place he found it difficult to breathe. He was lightheaded, and held on to Mizuki to keep his balance; the small action encouraged his teacher to go a step further.

Sei broke away with a yelp when Mizuki pushed him back against the small desk behind him. He took the hint and sat back, his legs forced apart for Mizuki to fit. He opened his mouth, prepared to protest, but no words came out. Instead a garbled moan took the place of reason; when Mizuki’s hand came down to stroke him through his pants. Sei bit his lip, trying to keep quiet. The desk made an awful squeak as he started to rock his hips forward, searching for more friction.

Mizuki took advantage of Sei’s distracted state, and tugged his head back with the hand still tangled in his hair. He started to layer kisses along the expanse of Sei’s pale throat, relishing the soft sounds leaving the teen. He picked a spot of flawless skin to bite into, licking and sucking little marks while tiny whimpers escaped Sei’s mouth. It was easier than expected to make the boy lose control, but it wasn’t all Mizuki wanted.

Sei was burning up. He was drowning. He’d never felt so good. He didn’t want it to stop, but he could feel himself nearing his edge already. Mizuki didn’t bother taking it slow; he enjoyed the strangled little sounds that left Sei’s throat with every stroke. His body was becoming too sensitive too quickly; given no chance to adjust to the unforgiving pace.

A few rough strokes had Sei falling.

“Ah – Sensei, don’t –!” Sei cried out. He gripped Mizuki’s wrist tightly, holding his hand in place. He couldn’t keep his body still. His hips jerked forward, grinding into the hand still wrapped around his cock, and forcing him over the edge.

A muffled cry left Sei’s throat and he collapsed forward against his teacher. His vision whited out for a moment and his mind vanished into the calm sensation of fingers carding through his hair.

“Good boy,” Mizuki murmured into Sei’s hair.

More than ever Sei felt like crying. His entire body was burning with shame. His legs felt like jelly, and his now filthy soul was weighing him down. He was ready to leave now. He wanted to go away. He wanted to stay put and finish what they’d started. Then he felt Mizuki’s hand untangle from his hair, and slide down to the curve of his ass. Sei’s voice came screaming back all at once.

“You – you – pervert!” he shoved his teacher away.

Mizuki laughed.

“I like to think of myself more as an opportunist.”

“I-I’m not an _opportunity._ I’m just a – I’m not a _thing!_ You can’t do this!”

Mizuki sighed, “Maybe not,” he said. Sei couldn’t believe how _casual_ he was being! He backed up and made his way back behind his desk, pretending nothing had happened at all. He held Sei’s failed test out to him. “Get your grandmother to sign this. That is, if you’d prefer not to make the grade up today.”

Sei’s face burned. He snatched the papers out of his teachers grasp, and stormed out.

* * *

 

That night during dinner, Sei said nothing. He thought about telling Aoba what was going on, but he could only _imagine_ the mess that would turn into. Aoba had enough trouble keeping _himself_ out of trouble. Sei even considered forging Granny’s signature, or having Aoba forge it for him, but in the end those papers stayed in his bag.

Sei lost himself in stale dinner conversation that didn’t change much from night to night. Granny would ask about their days and either one of them would get lost in a story. Granny would then eventually cut in, roughly claiming not to care very much at all. An outsider might believe her but Sei knew better.

Most nights she would ask about their classes. Most nights Sei would lie at least once – math was the only class he was consistently failing, but not the only area where he struggled. Aoba used to be the liar, the troublesome grandson, the one with terrible grades. But now even _he_ could get through a simple math class without the teacher making a pass at him.

At least one grandchild was doing well.

Once or twice Sei saw suspicious glances thrown his way, and eyes lingering on his neck. He kept his head down and hoped Aoba wouldn’t say anything. He took the very first chance to leave.

In his room Sei didn’t bother to turn on the lights. He stumbled over to his bed and sat on the very edge. From there he could just barely see the street through the crack in his curtains. They lived in a quiet area and there was no noise to keep his mind distracted. He could drown himself in social media, but was there really any point? His problems would still be there waiting.

Sei leaned back and stared up at the ceiling. He thought back to everything that had happened.

It was _insane_ really. For months he’d gone on thinking Mizuki-sensei hated him. And suddenly –

Why’d he have to make things complicated? It wasn’t as though Sei would’ve said no under different circumstances! Or… he would have? Really, he wasn’t sure. It wasn’t like he didn’t find Mizuki attractive but –

Sei was conflicted. He didn’t want to be manipulated, or treated like a cheap whore. At the same time he _really_ wanted it. Would it be so bad to give in? He could feel his heart beating beneath the persistent bruises on his throat; a reminder of everything that had happened and everything he could have.

He closed his eyes tight, placing a hand over them.

In the back of his mind he replayed the events of that afternoon. Every kiss, every touch, he wanted _more._ Sei pushed his shirt up, exposing his chest to the cold air. Would Mizuki-sensei touch him there too? He dragged a hand lazily up his chest, finding the sensation more ticklish than anything. It was nothing like the _real, raw_ feel of Mizuki’s hands on his body, but still elicited a response. He dug his nails in. Pale pink lines followed his fingers as they glided across his skin. The feeling was sharp – _biting_ – and drew a gasp from between his lips.

His hand stopped at the edge of his pants. He wondered if it was a strange thing to do, masturbating to thought of a teacher – or the thought of being blackmailed by one.

He decided to do it anyway.

Sei unbuttoned his pants. He didn’t want to ruin two pairs in one day. He couldn’t believe he’d done that – after barely being touched! He’d never been so embarrassed in his life. It made him feel _easy_ – like a total slut, desperate to be taken apart. Was that how Mizuki-sensei saw him? Was he just an object – a _game_?

Sei wasn’t surprised to find he was hard.

He hesitated before wrapping his fingers around the base of his cock. He began to stroke himself slowly, just to test the waters. He didn’t respond much at first – his own touch was too soft; it didn’t feel right. He remembered the way Mizuki had touched him. Sei tightened his hand just a little near the tip, and the added pressure caused his hips to jerk forward. Was it supposed to feel like that? It never had before. But everything with Mizuki had been so quick and _rough._ Like he didn’t care at all about Sei, only his body and the things he could do with it.

Sei _knew_ that thought shouldn’t have turned him on as much as it did. He shouldn’t _want_ to be objectified or _used._ At the same time he was pushing two fingers into his mouth. He imagined being pushed down to his knees, having his mouth forced open and Mizuki’s cock shoved past his lips. His fingers would thread through Sei’s hair, gentle at first; coaxing him to relax, to be better, to take more. Sei would do his best to keep up, to hear that husky voice praise him – to tell him he was good.

Sei wanted _desperately_ to be good.

He forced his fingers further into his mouth, almost gagging when they breached his throat. The feeling was awful. He loved it. He repeated the action, thrusting his fingers in an out of his mouth almost causing himself to gag again and again. He felt disgusting. He felt hot.

Sei’s hips were shaking, thrusting clumsily into his hand. He was already so close. He wanted to slow down and make himself last. He sped up instead. The edge was suddenly much closer than before. His stomach was knotting up, tightening, trying to force the pressure out. He couldn’t breathe – he didn’t _want_ to. His back arched off the bed as he came, biting his fingers to keep from crying out.

He crashed down from his high too quickly. He was left lying on his bed in a boneless heap, eyes wide open staring up at the ceiling. Sei felt _filthy_ , and even worse because he couldn’t wait to get more.

* * *

 

Sei was on edge all of the next day. He couldn’t keep still in a single one of his classes. He was called out a few times for it and even Clear called him _jittery_ – like he had any room to talk. Really he couldn’t find the will to care about any of that.

It felt like forever before last period math, and even after that it took another eternity for the class to end. He couldn’t focus at all; his mind kept wandering, and Mizuki didn’t help at all by _completely ignoring him._ Several times Sei decided he would just go home after the bell, and sign the papers himself, only to take it back right away. He was wound way too tight to bother lying to himself.

Mizuki took a longer time than usual assigning homework for that night. Sei didn’t bother; he knew he’d pass whether he did the work or not. He stayed put while everyone else left, though it seemed like they were all moving in slow motion. He’d shown up that morning without any patience but still couldn’t find it in himself to be mad when Clear bounced up to his desk, inviting him to third wheel an ice-cream date.

“Actually, I think I’m gonna hang back for a while,” He said, getting to his feet.

Clear nodded and rushed off, packed with far too much energy. Sei could definitely relate to that.

Mizuki-sensei was seated at his desk, pretending to go over something. Pretending he didn’t know what was going on.

“Do you need something?” he asked, as Sei made his way to the front of the room. A smirk curled the corners of his mouth. He looked up and his eyes were alight with a challenge Sei was _itching_ to accept.

Sei offered a coy smile in return. He could almost _hear_ the butterflies circling his stomach.

“Sensei~ I think I’m ready to make my grade up.”

He could tell by the shift of Mizuki’s expression, that he couldn’t take it back.

“I knew you’d be easy,” Mizuki said. The words set Sei’s skin alight. Then just as casually, he tacked on, “Take your clothes off.”

It wasn’t a suggestion, but an order; his way of asserting complete control over the situation. And it worked, because Sei wanted it that way too. He only hesitated for a split second. His fingers were trembling as he began to undo the buttons of his shirt. Each one exposed a fresh expanse of pale skin to Mizuki’s wandering eyes. He almost couldn’t stand it, but Sei forced himself to take it slow. He allowed his breath to hitch and his back to arch just slightly, as his fingers glided along his chest, and pushed the material off his shoulders. The belt came next; he pulled it off and tossed it to the ground. Sei made quick work of his pants; shifting his hips to wriggle out of them. He kept his gaze lowered as he continued to expose himself. He didn’t have the decency to be embarrassed anymore – and if he did, his awful teenage hormones twisted it up inside his head.

Mizuki took his time admiring Sei’s small body. His skin was mostly flawless porcelain, but Mizuki couldn’t help but notice a series of faded scratch lines layered along his chest. He dragged his eyes up the length of long legs, supple thighs and round hips. Sei’s cock was already standing at half-mast, overwhelmed by the situation. He _squirmed_ under Mizuki’s unforgiving gaze.

“Come here,” Mizuki said finally.

Sei was moving before he registered what had been said. Before he knew it he was standing in front of Mizuki, and being pulled down to sit on his lap. He balanced himself by grasping Mizuki’s shoulders, while his legs were forced apart, a knee on either side of the chair. He looked right into deep sea foam eyes, and realized the absurdity of the situation. He didn’t want to think about it at all, so he leaned down to kiss Mizuki.

Mizuki was surprised but not taken off guard. In a matter of seconds he’d coaxed Sei’s mouth open, teeth scarping lightly at his bottom lip – a _warning_ of what was to come.

Sei for his part, remembered not to breathe. It felt better that way, at least to him. he liked feeling light-headed, it made every sensation stronger; the feel of those rough hands gripping his hips too tight – surely tight enough to bruise – or the way his bare skin rubbed and chafed against Mizuki’s clothes, leaving bright pink or red on previously unmarked porcelain. He loved every scratch, scrape and bite. He wanted every bruise to last.

When Sei thought he couldn’t possibly hold his breath any longer, Mizuki pulled away.

Sei had no time to breathe. Mizuki pulled him closer, causing his balance to shatter. He wrapped his arms around Mizuki’s neck for support, and shifted his hips causing his breath to hitch as his cock was trapped between their bodies. He resisted repeating the action, afraid his already thin self-control would snap leaving him to rut against Mizuki like an animal in heat.

“Touch yourself,” Mizuki said, nipping at Sei’s jaw. The words were uttered so lightly they didn’t sound like an order at all.

Sei obeyed anyway, although hesitantly. He wedged a shaky hand between their bodies, to wrap _tight_ around the base of his cock. A gasp slipped from between his soft lips as he began to stoke himself roughly.

He let his eyes close, losing himself for a moment. Sei could almost imagine that his body wasn’t real and that he existed solely as a flame stoked by depravity. That was until Mizuki brought him back to reality; the solidity of his touch anchored him to that very moment. Sei began to think the real fire was blazing in those fingertips that dragged along his skin, tracing the pink scratches lined down his chest, carving new lines and indentions with delightfully blunt nails. It stung so much better that way.

A silent question hung in the air and Sei answered with a breathy moan, arching his back into the pain. He could feel himself getting too hot – his body getting too tight. Already his stomach was taut ready to release that wonderfully awful pressure. His hips stuttered. He slowed down. Sei didn’t want it to end so quickly.

“S-sensei I –”

“Keep going,” Mizuki said. He rested a hand on the small of Sei’s back, forcing his body to arch forward.

Sei continued stroking himself, feeling his skin burning inside his palm. His stomach was in knots. He almost crashed when Mizuki began to nip at his skin again, trailing light little bites down his throat, tearing at the skin most likely leaving all sorts of ugly bruises there for all the world to see and know exactly how Sei liked it.

That thought had Sei’s hips jerking forward, as he spilled all over his hand and Mizuki’s shirt with a sharp cry. He rode out his climax, grinding into his own hand as much as the small space would allow, until he crashed back into his own body. His legs ached from the position he was in, and his knees burned from rubbing against the fabric of the chair. His skin was so hot and he could feel his heart pounding in both his chest and throat. He didn’t move. Sei was afraid to open his eyes.

He could feel a hand gently rubbing his back.

“Good boy,” Mizuki whispered, setting his nerves on fire.

Sei could feel his stomach stirring again already. He lifted himself to look into those sea-green eyes, a mischievous mood growing inside him.

“Sensei, I don’t feel like I’ve _earned_ it,” he said, dragging his voice to make the sounds stretch in an almost child-like way which heavily contrasted his next words; “You _are_ going to _fuck_ me, aren’t you?”

Mizuki chuckled. The sound rumbled through his chest.

“I would’ve done this sooner if I’d known you would be so eager,” he said.

Sei wanted to bite back, but kept his mouth shut when his balance shifted again. Mizuki forced him to lean forward with his back arched and his ass jutted out. Mizuki then reached between them to ease Sei’s hand from around his cock where it rested loosely. Sei allowed his body to be twisted and bent until it became clear what Mizuki wanted, with his cum-soaked fingers resting against his own entrance.

Tentatively Sei began to prod against himself. He rubbed his fingers against his entrance, feeling his own cum soak into his skin. He found the area gave way easily enough after a bit of poking, for the first fingertip to slip in. at first he felt nothing, but a sharp pain caused him to cry out when he tried to push the entire finger inside too quickly.

Sei let out a breathless little laugh. “I wasn’t expecting that,” he admitted, mostly to himself.

Despite the pain – or perhaps because of it – he kept going; pushing the finger in and out, pulling and stretching himself until it no longer hurt. The second finger followed shortly after the pain faded to a dull ache. Sei became rougher with himself, thrusting his fingers inside carelessly causing tiny moans to slip from his mouth.

Mizuki watched over Sei’s shoulder as he continued to prepare himself. His ministrations sped up, with barely any time between the second and third finger, and certainly no stretching involved in the transition. Mizuki watched Sei drive his fingers in as far as they would go, the action bordering on violent. His mouth hung open, saliva coating his plump red lips and even dripping further down his skin. His head was thrown back and his hips were bouncing restlessly trying to get more.

“Sensei – sensei _please,_ ” the words fell from his mouth like honey. Sei’s dark eyes were alight with lust; all traces of fear and hesitation were gone.

Mizuki ran a hand through Sei’s hair. It was the only gentle touch he would allow himself. He brought his fingers to Sei’s mouth, pressing against his lower lip and even pausing to embed his nails there too. The action brought a breathy little sound forward; a cross between a moan and a laugh. Sei brought out his tongue to lap at those fingers, drawing them into his mouth, and Mizuki obliged.

Sei continued to thrust his fingers inside of himself, though his pace decreased significantly. His curiosity was piqued by the oddly morbid look his teacher gave him. He held his mouth open for Mizuki to explore, allowing his tongue to be pushed flat against the floor of his mouth. Those fingers twisted and turned, touching everything they could before Mizuki began to push them down even further.

Sei could feel himself gagging. He could feel himself starting to choke. He swallowed around Mizuki’s fingers when they breached his throat. He kept swallowing and holding his breath. He _couldn’t_ hold back the slew of moans brought forth by the disgusting feeling teetering on the edge of vomiting. Tears stung the corners of his eyes. They spilled over when Mizuki drew his hand away only to push his fingers back in.

He’d stopped moving altogether, but Sei didn’t notice until Mizuki’s other hand snaked it’s way behind him, gripping and squeezing Sei’s wrist.

“Don’t stop,” Mizuki ordered. He pushed against the back of Sei’s hand until he started fucking into himself again. For a very brief moment Sei was certain there was no way he could feel any better, until he felt something else prodding against his entrance, alongside his fingers.

Mizuki forced a finger inside of Sei. The gasp that resonated around his other hand almost destroyed his self-control. There was already very little stopping him from throwing Sei onto the desk in front of him, and fucking him for all he was worth. He wanted to _wreck_ Sei; to take him apart and break him piece by wonderful piece. He wanted Sei to beg for him, to belong to him, to want only him.

He continued thrusting his fingers into Sei. His body convulsed every time Mizuki touched the back of his throat, or rubbed that spot deep inside of him. Sei was a trembling mess grinding up and down in his lap, eyes begging for things he couldn’t name.

Mizuki withdrew his fingers from Sei’s mouth; certain he heard a disappointed whine follow them. He wiped them against Sei’s cheek, leaving shiny tracks of saliva behind.

“Sensei, I can’t take it anymore,” Sei cried out when their fingers hit that spot inside him. “Please – _please_ fuck me already.” All the while he continued to bounce up and down in Mizuki’s lap.

Mizuki gripped Sei’s wrist, forcing him to stay still. He hummed pensively.

“I’m not sure if you deserve it,” he teased.

“I _need_ it – I need _you_ inside me,” Sei said, his voice rough with desperation, “Please Sensei, I wanna feel your cock wrecking me inside.”

Mizuki decided that was enough. He withdrew his hand, pulling Sei’s along with it. The next thing Sei knew, he was being moved again. He was lifted to his feet, turned and pushed chest flat against Mizuki’s desk.

Sei listened to the sound of shuffling behind him. His heart stuttered at the sound of a zipper being undone.

Mizuki spat into his hand, using it to coat his erection with several short strokes. He couldn’t resist reaching forward to brush his thumb against Sei’s entrance, earning a sharp gasp and a childish little whine from the boy. Sei went so far as to wriggle his hips impatiently, only getting a harsh smack for his efforts.

Sei cried out, and Mizuki noticed a red shadow _already_ appearing on his smooth white skin. He entertained for a moment, the idea of Sei’s entire rear coated in angry red welts, body wracked with uncontrollable sobs, voice wailing out louder and louder with each hit. It was enticing, but something he would have to explore later. Neither of them had the patience, let alone the time for it right then.

With one hand flat against Sei’s back, Mizuki drove forward in one brutal thrust, bottoming out completely all at once. Sei let out a strangled little sound, pushing his hips back, pressing himself against the solid form lingering behind him. His fingers never could’ve prepared him for the real thing. His body ached, a distinct feeling of fullness pushed against his stomach in the best possible way starting out dull and quickly becoming unbearable. It was too _much_! Sei could barely breathe, pressed harshly down against the desk he could only take in small puffs of air and pray the burning stretch screaming through his body _never_ went away.

Sei shifted his hips impatiently – they dug against the hard wooden edge of the desk, _almost_ cutting into his skin – and let out a gasp when the movement caused Mizuki to shift inside him. he could feel himself twisting and stretching inside, simultaneously trying to force Mizuki out, and hold him in place.

“ _sensei~_ ” he whined, starting to bounce his hips but making very little progress. “fuck me already.”

The hand on his back slid down his body, causing Sei to shudder. Mizuki gripped his hips tightly and held him still as he started to fuck into his small body.

Sei’s body was already worn out and sensitive from his previous orgasm. He remained draped over the desk almost completely limp while Mizuki used him. The pace was brutal, he barely had time to adjust to it at all, and every wonderful feeling was accompanied with an undertone of pain.

Sei loved it, he loved every second of it, could feel himself transcend in a moment where he didn’t have to physically exist or at least didn’t have to control his physical form. He could exist solely through the nerves in his body pulsing with every sharp sensation that shook him closer and closer to that amazing edge. He was hardly aware of the sounds he made, spewing from his mouth, or the pool of saliva smearing across his face. Everything was a wonderful blur pushing him towards darkness and light and _god_ he wanted desperately to let go and fall.

When Sei did reach his limit it was with a breathless cry and a jerk of his hips. He came all over the desk in front of him, his body tightening around Mizuki’s cock, and stuttering in his grasp. His hips bounced back in an effort to ride out his second orgasm, only bringing Mizuki closer to his own edge. With a few more rough thrusts he was emptying himself inside of Sei, earning only a completely blissful sigh from the younger boy.

Given a few minutes to calm down, Sei came back to his own body. Everything ached, he felt so heavy and _dirty,_ covered in sweat, saliva and – other things. He began to laugh, although it caused a sharp pain to dance through his ribcage.

“Oops,” he managed to say.

Mizuki laughed behind him, peeling himself away and withdrawing his softening cock. The action caused a small amount of cum to leak out before Sei could stop it. It was so sticky and wet, the thought would’ve excited him if Sei wasn’t so tired.

“That’s a bit of an understatement,” Mizuki said.

Sei’s eyes drifted closed. He was vaguely aware that his body was being moved but he couldn’t find the will to care. Eventually he found himself propped onto a chair half-dressed, while Mizuki fumbled the buttons of his shirt. A smile quirked the corners of his mouth and Sei opened his eyes, a cheeky glint restored within them.

“So, do I pass?”

**Author's Note:**

> This took me like a month to write. i literally stopped living my life, and sacrificed my soul to the dark lord so i could give the world this piece.


End file.
